Abstract: Cloning and bioinformatics analysis of m~6A methyltransferase gene METTL3 in Hu sheep（Ovis aries） were performed in this study to explore its molecular characteristics and spatiotemporal expression change rule. Using muscle cDNA of Hu sheep as template, the coding sequence（CDS） region of METTL3 gene was cloned, and the similarity alignment, phylogenetic tree construction and bioinformatics analysis were carried out by using bioinformatic software. Real time quantitative PCR analysis was performed to test METTL3 mRNA expression in 9 different tissues of Hu sheep. The results indicated that the complete CDS of the Hu sheep METTL3 gene was 1 739 bp in length and encoded 579 amino acids. The genetic relationship of METTL3 gene between Hu sheep and goat（Capra hircus） was the closest. The isoelectric point of METTL3 protein was 6.05, with the half-life of 30 h, unstable and hydrophilic. METTL3 had a conserved MT-A70 domain without a signal peptide and transmembrane structural domains. A total of 59 potential phosphorylation sites were predicted. The advance structure of METTL3 protein was composed of irregularly coiled（50.09%）, α-helix（33.85%）, extended chain（12.44%）, and β-turn（3.62%）, which was closely related to METTL14, WTAP and other related protein involved in the methylation process of m~6A. According to real time quantitative PCR results, the METTL3 mRNA was wildly expressed in all nine tissues of Hu sheep. Compared with longissimus dorsi, the expression of METTL3 mRNA was higher in kidney, spleen, and subcutaneous fat（P＜0.01）. This study successfully cloned and obtained the full-length sequence of the CDS of the METTL3 gene, and preliminarily studied its expression variety rule in different tissues of Hu sheep, which provided theoretical basis for studying the role of the METTL3 gene in mammalian growth and development.